lurmann



Pgtnitrh tates ntrnt fff' IMPnovBMBnr ni eAsTv-FURNAOS,

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To ALL wHoM 11' MAY coNeERNz Be it known that I, F. W. RMANN, ofOsnabruck, in the Kingdom of Prussia, have iuvented a new and usefulmPl'OVCmCH? in BlaS-Furnaccs; and I do herebydeclarc that the followingis a full, clear, and cxact description thereof, which willfenable thoseskillcd in the art to make and use the same, reference being had to theaccompanying drawing, forming part of this specification, in whichdrawing- Figure 1 is a Vertical central section of a furnace' to whichmy improvement is applied..

Figurc 2 is a hprizont'al section through the tuyeresL' i i Figure 3 isa front elevation of the slag-discharge piece detached.

Figure 4 is a Vertical section of the latter, also dct'ached'.

This invention relatcs to furnaces for smelting iron orc, and has forits object to dispensc with the tymp" or fora-hearth ond the wall-stonenow in common use in iron blast-furnaces, and to i'eplace the tymparrangement by such a construction as allows the slag to bc tappeddirectly from the hearth. In the tymp arrangement the slag is driven outof the furnace by being first forc'ed below the tympstone, whichprojects below the level of the tuyeres and intcrccpts the currents of'air, and prevents their escape with the slag, which stands in the vtymp'at the same level ason the hearth, the slag being'discharged onlyr whenit rises-in the tymp high enough to ovcrilow the top of the wall-stonethat forms thebo'titom of the discharging'orifice. By this amn'gcmentthetymp-stonc constitutcs a trap which intercepts the eurrents of air, andcauses their pressure to be exerted directly on the surface of the slagon thehearth. This method of construction has several disadvantages, oneof which is the diflicultyof keeping the tymp-stone and the surroundingparts in repair; another is, that the pressure-of the currcnts of air orwind is limited and counteracted-by the counter-pressure of thecolumn'fl of slag in the tymp; and another is, that one side of thefurnace being ocoupied by the tymp, no tuyere can be applied oa=`that'side, and consequently the supply of wind is irregularlydistrihuted.

My invcntion avoids or overcomes these disadvantages in a simple andeifective manner.

In this example of my invcntion the letter 1A designates the furnace,and B several 'tuyeres, which are arrangcd therein at a proper height.My furnace has no tymp, and the sidcs of the hearth, whether round o rsquare, extend clear down to the bottom stone, the usual opening (notshown in the drawing) being made in the lower part of the hearth, forthe discharge of the iron. The openings of or the tuyeres B aredistributed at equal distances apart in the sides of the hearth. At asuitable height from the bottom-stonc I leave an opening in the hearth,in which I place a cast--iron or brass slag-discharge piece, D, which iscast or made with numerous channels or pipes, running up and down or inother dircctions through it, as shown in figs. 3 and 4. The piece D isformcd with a dove-tail on its upper end, which is fitted into thebottom of a stationary metallic plate, O, connected with the furnace.This plate is also cast or made with channels or pipes running throughit, and the channels or pipes of said plate and of the piece D may be soarranged as to connect or communicate with each other when the plate Cand fpicce D are in their proper positions, or they may be independentof each other.

The object of the said ehannels or pipes .pis to permit the plate C andpiece D to hc cooled, by forcing water` through them while the furnaceis in operation, proper ,connections being made for that purpose with areservoii" of cold water, or with a force-pump. One or more holes aremade in said piece D, through which the sla'g is discharged, the Shapeof said holes being shown in figs. 3 and 4, the middle portion beingcylindrical, but each end being conical or flaring: The dimensions ofthe slagdischarge piece are a little less than the opening in which itis placed, and the space left around it is filled with sand, which canbc readily remo'ved in case it is dcsired to remove the piece D torepair it, or if it is desired to have an opening in the hearth to workthrough, as when any irregularity in the smelting process has takenplace. The fiow of cooling-water through the slag- (lischarge piece D isregulated for the purpose of controlling discharge of the slag throughit. By allowing much Cooling water to circulate through itswaterchanne'ls or pipes, the temperature of the piece D is lowercdsufliciently to allow a coating of slag to adhere and choke itsdischarge openings, which are of less diameter in the middle than attheir ends. By reducing the flow of eooling-watcr the piece 4is allowedto retain a higher' tcmperature,and in consequence the slag is meltedout of the discharge-openings, and they become' clear and open, andpcrmit the slag to flow without intcrrup'tion. When the slag in thehearth is lower than the level of lthe dscharge-opcnings, thelattorarc-simply'closed by an iron rod.

My invention canhbe easily applied, by thoseski'llcd in the art to whichit belongs, to blast-furnaces of' the common construction.

The invention is attended with several advantages over the common methodof constructing or nrronging furnaces, among which I mention thefollowing:

First. It permits a. higher pressure of wind.

Second. The henrth is preserved in better condition than where thecommon mode of construction is retoinod.

Third. The lbor of the operation of smelting is lessencd.

Fourth. It allows one more side of the hearth for a -tuyere.

Ffth. It zwoids the stoppnges of the wind supply, now necessary as oftena'' the iron is dischnrged.

Sixth. A considcrnble increase is goined in the product of the furnace,while nt the same time the costof labor and repairs is lessened.

What I cloim as new, and desire to secure by Letters Patent, is-'- 1.The slag-diseharge piece D, constructed and arrange. substzmtially asdeseribed.

2. The slag-discharge piece D, in combination with the plate O, to whichit is fittcd substnntially as describcd.

3. The shape of the discharge-opening or openings of the`` piece D,being made flaring at its encls, and of dininished diameter in the middle or central part, substantially os deseribed.

4. Combning with the sIag-discharge piece o series of water-Channels orpipes, substantinlly us and for the Purpose above set forth. i 5.Combining with the metallic plate C :Lv series of Water-chnn'nels orpipes, substnntinlly ns and for the purpose chore set forth;

6. The method of controlling the discharge of sing from blast-furnaces,by regulnting the slag-discharge piece, substantially :ts described.

vThis specification'signed by me this twelfth (lay of July, 1867.

' F. W. LURMANN'.

the temperature of Witnesscs z A. STEINHOFF, E. SCHEMMANN.

